While the first teardowns of the iPhone 4 (excluding Gizmodo’s crude vivisection) were extremely exciting due to the novelty of the design, the 4S doesn’t have much to offer. The stem of the iPhone 5 hopefuls’ slight disappointment, i.e. that the 4S is essentially a spec bump, meant that this teardown would necessarily be less than thrilling.
The biggest change is, of course, the addition of the larger and more powerful A5 chip. Not much more is known about it now than when it first appeared in the iPad 2, but it’s there, that much is certain. The wireless chips have been upgraded to allow for the quadband and HSPA+ functionality, but there’s not much to say about that.
The vibration motor (right, below) has been switched out for a nicer one that’s less buzzy, apparently. Not having felt either device buzz, I can’t say whether it’s an improvement, but I don’t think Apple would have switched this out if they were happy with its performance.
That’s pretty much all. A few minor changes in layout and soldering to accommodate the larger A5 die and such are also to be found, but they’re not substantial.